<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>双飞翼布局</title>
</head>
<style>
    .main,
    .left,
    .right {
        height: 150px;
        float: left;
    }

    .main {
        width: 100%;
    }

    .container {
        background: red;
        padding: 0 200px 0 300px;
        height: 100%;
    }

    .left {
        background: yellow;
        width: 300px;
        margin-left: -100%;
    }

    .right {
        background: green;
        width: 200px;
        margin-left: -200px;
    }

    body::after {
        content: ""
    }
</style>

<body>
    <div class="main">
        <div class="container">中间</div>
    </div>
    <div class="left">左边</div>
    <div class="right">右边</div>
</body>

</html>